hadbetter后面加动词什么形式

had better的意思是（用于建议、警告、威胁、发表意见等）最好。had better加动词原形，had better do sth最好做某事。 

had better的用法

had better(常简略为'd better)是一固定词组，had better"最好"，用于表示对别人的劝告、建议或表示一种愿望。

一、had better后面必须跟动词原形。

had better后跟动词原形(即不带to的不定式)，构成had better do sth.句型。

这里的had不能用have来替换。如：

You'd better go to hospital at once.你最好立即去医院看病。

Tom, you'd better go there today.汤姆，你最好今天去那儿。

二、主语不论是第几人称，句子不论是什么时态，都要用had better的形式。如：

Now you(he，we) had better listen to the teacher.你(他，我们)现在最好听老师讲。

三、had better可用于的时态。

1.had better用于指现在。如：

Now you had better listen to the radio.你现在最好听收音机。

You had better be quiet.你最好安静一些。

2.had better用于指将来。如：

You had better start tomorrow.你最好明天动身。

We had better buy the more expensive one. It will last much longer and so it will be cheaper in the end.我们最好还是买贵些的,它更经久耐用，所以到头来，它还是更便宜些。

3.had better用于进行式，表示讲话人提出建议时，动作正在进行。如：

We had better be watching the TV play.我们最好现在就看到电视剧。